Dementia is a morbid condition in which difficulties lie in everyday life because of continuous decline of intellectual skills such as memory, language, judgment, thinking abilities and the like due to damages in brain function. Dementia, a representative disease of cognitive disorders, is a morbid phenomenon that should be distinguished from normal aging. Dementia is categorized into Alzheimer's disease, vascular dementia, alcoholic dementia, traumatic dementia and dementia due to aftereffects of Parkinson's disease depending on its causes. It is known that Alzheimer's disease accounts for 50% to 70% of diseases causing dementia, and vascular dementia is known to be the second most frequent cause of dementia. The proportion of dementia patients are rapidly increasing in South Korea and it is expected to be accelerated further. Therefore, demand for development of functional substances and food and the like for preventing and treating cognitive diseases including dementia is growing in these days.
Apropos of Alzheimer's disease, decline of acetylcholine function in the central nervous system is the most common phenomenon. Therefore, administration of acetylcholine precursors or drugs inhibiting decomposition of acetylcholine for increasing concentration of acetylcholine in brain has been used to treat Alzheimer's disease. Thus, single use of acetylcholinesterase inhibitors or combined use with previous cholinesterase inhibitors is used as a medicament for Alzheimer's disease. Representative drugs would be tacrine, donepezil, rivastigmine, galantamine and the like.
Vascular dementia due to stroke or palsy is mostly caused by damages to the brain cells due to insufficient blood supply to many areas of the brain by cerebrovascular atherosclerosis. An anticoagulant such as aspirin and warfarin and the like is being used as a platelet aggregation inhibitor, which prevents cerebrovascular diseases that could occur from thrombus for treating vascular dementia.
Drugs in use of treating Alzheimer's disease or vascular dementia merely delay the progression of disease and not that effective in direct treatment. Also, therapeutic range of these is limited to the initial stage, therefore the efforts to develop a drug for treating the root cause of dementia have been made. Reasons for onset of vascular dementia and Alzheimer's disease are different, but both eventually impairs the memory in common (Terry and Buccafusco, 2003; Kar et al., 2004; Akhondzadeh et al., 2008; Cummings et al., 2008; Voss et al., 2008).
Meanwhile, although anxiety is recognized as a normal response to adapt to the changing circumstances, but when excessive anxiety persists for more than 6 months, it can be deemed to be an anxiety disorder. Morbid anxiety can cause severe pain to the patients themselves as well as their family and surrounding people, and the reason of it is known as an abnormal nerve structure. Anxiety disorder treatment is accompanied with psychotherapy and medicine treatment, and drugs having various routes of action mechanism are used for the medicine treatment. However, use of anti-anxiety drugs should be made cautiously because of anxiolytic effect as well as side effects such as withdrawal and sedation symptoms. Accordingly, investigation on anti-anxiety drug without side effects, which is made of natural substances, has emerged as a major problem.
Hypersomnias means a lot more sleep than a normal sleep. It is a status of feeling fatigue and causing problems to attention ability due to constant awareness of lack of sleep even though there was enough sleep and no specific reason. Attention ability is important for learning or judging something, and maintaining concentration is a major factor in making quick decision and judgment that can lead to the most effective action while conducting series of work. However, maintaining concentration for a long time is very difficult because it is hindered by various external factors, and substances having awakening effect, which can extend duration of concentration, have been researched. Glucose intake and substances such as caffeine and the like, which increase mind concentration while workout, are known to be effective for short-term increase of concentration. However, glucose can increase blood sugar temporarily but has no continuity, and caffeine has relatively longer duration but has symptoms of intoxication when taking it excessively. Thus a novel drug that has no toxicity and longer duration is required.
Accordingly, the present inventors discovered a herbal extract and its active ingredients, which can effectively increase memory and learning abilities, while researching on development of effective therapeutic agents for preventing or treating cognitive disorders such as dementia and the like, and found out that the same has superior effect in concentration, anti-anxiety effect and awakening effect as well as memory when applying the same to various psychoneurological diseases. Succeedingly, the present inventors completed the present disclosure.